What is proof of existence?
In simple terms, proof of existence is evidence that a particular piece of digital content existed in a particular form by a certain time. A common way to create that evidence is to calculate a cryptographic hash of the content and timestamp the hash.
The hash acts like a digital fingerprint. The timestamp connects that fingerprint to an earlier point in time without requiring the original content to be placed directly on a public ledger.
How HashMyWords creates the record
Can proof of existence be private?
The file itself can stay private because it remains on your device, but current H2 file proofs deliberately publish its standard SHA-256 on Hedera. Private text is different: the plaintext and private salt stay in your browser and only the resulting salted SHA-256 hash is submitted.
Keep your original material and receipt. An H2 SHA-256 does not contain the file bytes, but it can identify an exact candidate file to someone who already possesses that file, so do not create an H2 file proof if you do not want the fingerprint to become public and persistent.
What does it prove — and what does it not prove?
It can help demonstrate:
- that a matching digital fingerprint was recorded by a certain time;
- that the content you hold now matches the content represented by that fingerprint; and
- that the relevant Hedera transaction exists independently on the public ledger.
It does not automatically demonstrate:
- who created the content;
- who legally owns it;
- that the content is accurate or truthful; or
- what legal weight a court or other decision-maker will give the record.
Good evidence is more than one timestamp
If the material matters, keep a sensible evidence trail. Preserve the original file or text, the HashMyWords receipt, any surrounding drafts or records, and information showing how the material was created or controlled. A timestamp is one strong technical fact within that wider context.
Frequently asked questions
Is a hash the same as proof of existence?
No. A hash identifies the state of content, but a timestamp is needed to link that fingerprint to a point in time.
Does proof of existence reveal my content?
Not necessarily. A cryptographic fingerprint can be timestamped without publishing the original content.
Can the recorded Hedera transaction be edited by HashMyWords later?
Once confirmed on Hedera, HashMyWords cannot simply rewrite or delete that public ledger transaction.
Is proof of existence the same as copyright registration?
No. A technical timestamp and a formal legal registration are different things. Requirements and legal effects depend on the relevant jurisdiction and context.